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GSE46818
Homo sapiens
9 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Wnt signaling potentiates nevogenesis.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Melanocytes within benign human nevi are the paradigm for tumor suppressive senescent cells in a pre-malignant neoplasm. These cells typically contain mutations in either the BRAF or N-RAS oncogene and express markers of senescence, including p16. However, a nevus can contain 10s to 100s of thousands of clonal melanocytes and approximately 20-30% of melanoma are thought to arise in association with a pre-existing nevus. Neither observation is indicative of fail-safe senescence-associated proliferation arrest and tumor suppression. We set out to better understand the status of nevus melanocytes. Proliferation-promoting Wnt target genes, such as cyclin D1 and c-myc, were repressed in oncogene-induced senescent melanocytes in vitro, and repression of Wnt signaling in these cells induced a senescent-like state. In contrast, cyclin D1 and c-myc were expressed in many melanocytes of human benign nevi. Specifically, activated Wnt signalling in nevi correlated inversely with nevus maturation, an established dermatopathological correlate of clinical benignancy. Single cell analyses of lone epidermal melanocytes and nevus melanocytes showed that expression of proliferation-promoting Wnt targets correlates with prior proliferative expansion of p16-expressing nevus melanocytes. In a mouse model, activation of Wnt signaling delayed, but did not bypass, senescence of oncogene-expressing melanocytes, leading to massive accumulation of proliferation-arrested, p16-positive non-malignant melanocytes. We conclude that clonal hyperproliferation of oncogene-expressing melanocytes to form a nevus is facilitated by transient delay of senescence due to activated Wnt signaling. The observation that activation of Wnt signaling correlates inversely with nevus maturation, an indicator of clinical benignancy, supports the notion that persistent destabilization of senescence by Wnt signaling contributes to the malignant potential of nevi.
Publication Title
Wnt signaling potentiates nevogenesis.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Mutations in both RAS and the PTEN/PIK3CA/AKT signaling module are found in the same human tumors. PIK3CA and AKT are downstream effectors of RAS, and the selective advantage conferred by mutation of two genes in the same pathway is unclear. Based on a comparative molecular analysis, we show that activated PIK3CA/AKT is a weaker inducer of senescence than is activated RAS. More-over, concurrent activation of RAS and PIK3CA/AKT impairs RAS-induced senescence.
Publication Title
Activation of the PIK3CA/AKT pathway suppresses senescence induced by an activated RAS oncogene to promote tumorigenesis.
Sample Metadata Fields
Cell line
View Samples- Mus musculus
- 9 Downloadable Samples
Illumina Genome Analyzer IIx
Description
OIS is characterized by a stable proliferation arrest and secretion of pro-inflammatory cytokines and chemokines, the senescence-associated secretory phenotype (SASP). Proliferation arrest and the SASP collaborate to enact tumor suppression, the former by blocking cell proliferation and the latter by recruiting immune cells to clear damaged cells. However, the interactions of OIS cells with the immune system are still poorly defined. Here we show that engagement of OIS in primary human melanocytes, specifically by melanoma driver mutations NRASQ61K and BRAFV600E, causes expression of the MHC class II antigen presentation apparatus, via secreted IL1ß signaling and expression of CIITA, a master regulator of MHC class II gene transcription. Overall design: We quantify transcription via high throughput RNA sequencing in nevus melanocytes in cross FVB/NJ mice with Cre inducible NRAS61K with an MHCII cross
Publication Title
Oncogene-Expressing Senescent Melanocytes Up-Regulate MHC Class II, a Candidate Melanoma Suppressor Function.
Sample Metadata Fields
Cell line, Subject
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
SWP73 subunits of SWI/SNF chromatin remodeling complexes (CRCs) are involved in key developmental pathways in Arabidopsis. We found, using microarray that inactivation of SWP73B caused altered expression of genes belonging to various regulatory pathways, including leaf and flower development. On the basis of this experiment and our other data we concluded that SWP73B modulates major developmental pathways.
Publication Title
SWP73 Subunits of Arabidopsis SWI/SNF Chromatin Remodeling Complexes Play Distinct Roles in Leaf and Flower Development.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 4 Downloadable Samples
- IlluminaGenomeAnalyzerIIx
Description
IMR90 cells were passaged until replicative senescence and compared with proliferating cells. Overall design: We used RNA-Seq to detail the global programme of gene expression in human IMR90 replicative induced senescence
Publication Title
Mapping H4K20me3 onto the chromatin landscape of senescent cells indicates a function in control of cell senescence and tumor suppression through preservation of genetic and epigenetic stability.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 4 Downloadable Samples
- IlluminaGenomeAnalyzerIIx
Description
IMR90 cells were infected with pLNC-RAS:ER (from Jesus Gil lab) with retroviral gene transfer. Infected cells were drug selected G418. The cells were induced either with ethanol as control or with 100nM final conc 4-hydroxytamoxifen (sigma H7904) for ectopic expression of protein Overall design: We used RNA-Seq to detail the global programme of gene expression in human IMR90 oncogene induced senescence
Publication Title
Mapping H4K20me3 onto the chromatin landscape of senescent cells indicates a function in control of cell senescence and tumor suppression through preservation of genetic and epigenetic stability.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2500
Description
Since the discovery of induced pluripotent stem cells there has been intense interest in understanding the mechanisms that allow a somatic cell to be reprogrammed back to a pluripotent state. Several groups have studied the alterations in gene expression that occur as somatic cells modify their genome to that of an embryonic stem cell. Underpinning many of the gene expression changes are modifications to the epigenetic profile of the associated chromatin. We have used a large-scale shRNA screen to identify epigenetic modifiers that act as barriers to reprogramming. We have uncovered an important role for TRIM28 in cells resisting transition between somatic and pluripotent states. TRIM28 achieves this by maintaining the H3K9me3 repressed state and keeping endogenous retroviruses silenced. We propose that knockdown of TRIM28 during reprogramming results in more plastic H3K9me3 domains, dysregulation of genes nearby H3K9me3 marks, and up regulation of endogenous retroviruses, thus facilitating the transition through reprogramming. Overall design: Gene expression profiling using high through put sequencing at day 7 of Oct4, Sox2, Klf4 and cMyc (OSKM) expression in mouse embryonic fibroblasts with or without Trim28 / Setdb1 knockdown
Publication Title
TRIM28 is an Epigenetic Barrier to Induced Pluripotent Stem Cell Reprogramming.
Sample Metadata Fields
Specimen part, Cell line, Treatment, Subject
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Activation of the hypoxia inducible transcription factor HIF-alpha and the NF-kappaB pathway promotes inflammation mediated tumor progression.
Publication Title
The hypoxia-inducible transcription factor ZNF395 is controlled by IĸB kinase-signaling and activates genes involved in the innate immune response and cancer.
Sample Metadata Fields
Cell line, Treatment
View Samples- Homo sapiens
- 2 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
We have performed whole genome expression arrays covering over 47000 transcripts comparing the transcriptional profile of NKp80+ to NKp80- CD8+ CCR7- alpha beta T cells. A highly similar global gene expression profile was observed between both memory phenotype T cell subsets. Interestingly, the majority of differentially expressed genes are immune-associated. NKp80+ cells contained markedly increased levels of transcripts encoding for MHC class I and II molecules and for numerous members of the KIR family. Also other NK-related transcripts were more abundantly expressed in the NKp80+ subset. With regards to cytokines, chemokines and their receptors, transcripts important for homeostasis and proliferation are expressed differently. Also transcripts encoding for adhesion molecules are present at different levels in both T cell subsets. Further cytotoxic effector molecules are expressed differently.
Publication Title
NKp80 defines and stimulates a reactive subset of CD8 T cells.
Sample Metadata Fields
Sex, Specimen part
View Samples